Welcome to the STD forum. I'll try to help.
You are infected with HSV-2. Despite the lab's apparent confirmation policy, it probably isn't necessary; type-specific HSV-2 antibody tests with ELISA ratios over 3.5 almost always are truly positive. At 5.5 there is little doubt in your case. I'm not sure what confirmation test they are referring to -- perhaps what is called an inhibition assay. But I think it's moot in your case.
About 20% of adults in the US have HSV-2 and most never had (or do not recall) symptoms that suggest herpes. However, many such persons come to recognize symptoms once they know about the blood test results. If you stay alert you may find you are having mild but typical outbreaks. If so, they likely to show up as one or more mild, small sores that would appear every time in more or less the same spot (give or take an inch) and reappear no more often than every 1-2 months. Or maybe never.
As the partner of a man with known genital herpes, he is a logical source -- but it could be you both are infected but not necessarily from each other. In any case, couples do not "ping pong" HSV-2 back and forth. You and your partner both are immune to catching a new HSV-2 infection from each other (or from anyone else). There need be no limits or restrictions on sex between you, unless required for comfort -- i.e. if there is a painful outbreak, avoiding sex would make sense. Otherwise, no worries.
But a last bit of caution: It sounds very likely that your partner indeed has HSV-2. However, since his infection has never been confirmed, you and he might consider it, i.e. he could have a blood test just to be certain.
I hope this helps. Best wishes-- HHH, MD